Scheduled for Execution

Travel to the northeast corner of the Imperial City and you'll find the entrance to the sewers along the water. Unlock the sewer gate with the key given to you by Valtieri and follow the compass arrow through the dingy passage. You'll encounter mudcrabs and rats along the way, but nothing more than that...until, of course, you finally push through the entirety of the sewers and emerge inside the prison.

Before you make yourself known to the guards, here's a couple of things to keep in mind. First, guards will attack you even if you don't pick a fight. Second, if you don't attack back you will not get a bounty. This is good.

When you're ready, charge into the prison and make a mad dash towards the arrow on your compass. You'll pass through a number of doors before finally arriving at the prison cells. Valen Dreth will initiate a conversation with you automatically. As he tries to break out, throw up your guard and talk to Valen to yield to him, then break him out of his cell.

Valen Dreth will make a mad dash for the exit. You can try to kill him yourself or wait for a guard to kill him. We let the guards kill him for fear that our own blade swipes might accidentally hit one of the guards. With Dreth dead (and no guards harmed), high-tail it back through the sewers to exit the Imperial City prison.

More than likely, the guards will still be chasing you, an unfortunate fact that prevents you from fast traveling. Make a beeline back towards Cheydinhal and eventually the guards should give up their pursuit. Return to Valtieri and speak to him to complete the quest.